<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <script>
    var arr = [[12, 59, 66], [100, 888]];       // 创建二维数组
    for (var i = 0; i < arr.length; i++) {      // 遍历数组arr
      for (var j = 0; j < arr[i].length; j++) { // 遍历数组arr的元素
        console.log(arr[i][j]);                 // 输出二维数组中每个元素
      }
    }
  </script>  
</body>
</html>